Threading, drilling, and reaming machine



July 24, 195] H. E. PRUITT 2,561,992

THREADING, DRILLING, AND REAMING MACHINE Filed May 17, 1948 I 4 Sheets-Sheet 1 /7 I 7- 7 /6 64" Z7 .Z

July 24, 1951 H. E. PRUITT THREADING, DRILLING, AND REAMING MACHINE 4 Sheets-Sheet 2 Filed May 17, 1948 3 m HEP?" 24 2'27 y 1951 H. E. PRUITT 2,561,992

THREADING, DRILLING, AND REAMING MACHINE Filed May 17, 1948 4 Sheets-Sheet 5 HEPWQ 2?? I July 24, 1951 I H. E. PRUITT 2,561,992-

THREADING, DRILLING, AND REAMING MACHINE Filed May 17, 1948 4 Sheets-Sheet 4 Patented July 24, 1951 OFFICE I THREADING, DRILLING, AND REAMING AoHnvE Harvey E. Pruitt, Cheboygan, Application May 17, 1948, Serial No.:27;515'

. 1 Thisinvention relates to screw threading-ma,- chines and is an improvement over the threading machine embodied in my prior patent, No. 1,691,825, issued November 13, 1928, for Nut Tapping Machine.

An object of this invention is to provide a threading machine wherein either internal or external threads may be formed on the work.

Another object of this invention is to provide athreading machine of this kind embodying the use of at least two threading spindles with a work carriage for each spindle and means for alternatelymoving the carriages so that while one piece of work is being threaded the other carriage may be loaded with a new work piece. In this manner the machine is capable of being operated continuously so that the threading operation may be rapidly performed on the production basis.

' A further object of this invention is to provide a threading machine of this kind which is so constructed and arranged that difierent types of threads may be out without change in the machine. In the embodiment of this invention shown in the drawings each carriage is moved forward under the action of a feeding cam which bears against a spring-pressed collar correlated with the carriage so that when the die or tap takes hold on the work the latter will be moved under the combined action of the feeding cam and the threading operation with the end thrust on the spindle and die or tap being substantially counterbalanced by the spring-tensioned feeding of j the work.

A further object of this-invention is to provide a machine of this kind which may be used for threading, drilling or reaming, the character of the operation depending upon the kind of tool secured to the chuck or spindle head. To the foregoing objects, and others which may hereinafter more fully appear, the invention con- 's'ists of the novel construction, combination and arrangement of parts, as will be more specifically referred to and illustrated in the accompanying drawings, but it is to be understood thatchanges, variations, and modifications may be resorted to which fall within the scope of the invention as claimed.

In the drawings: v

Figure l is a detailed side elevation, partly broken away and in section, of a machine constructed according to an embodiment of this invention.

Figure 2 is a plan view of the device with the topof the headstock removed.

3 Claims. -105) die, with the .taps and dies. of conventional con Figure 3 is a fragmentary vertical section through the upper portion of the device.

Figure 4 is a fragmentary sectional view taken on the line l-e-lof Figure 3.

'Figurefi. is a fragmentary sectional view taken on the line. 5-4. of: Figure 1.

Figure :6 isa fragmentary section view taken on thelineE-PG of Figure 2.

Figure 'I is a fragmentary sectional view taken on the line l-l' of Figure" 2.

Referring to the drawings, the numeral 10 designates generally a hollow base or bed havin a. top wall. I] disposed in horizontal position. Thebase H! has mounted on the top wall H thereof. a headstock, generally designated as i2 and the headstock [2 includes a housing formed of upright side, walls l3 and upright end. walls M and I5. A cover or closure I6 is securedby fastening devices I! on the upper edges of the upright walls I3, l4 and 15. A

drive shaft [8 is journalled through the walls Hand 15 of the housing or headstock I2 projecting through the rear'wall l4 and a pulley I9 is secured to the rear end of the shaft l8.

A motor or power member 20 is mounted in the. base 10 being constructed in the form of an electric :motor which is mounted on a bracket or supporting means 2|. The motor 20 includes a :shaft 22 on which a pulley- 23 is secured and "respectively.- The drive shaft l8 has secured thereto a gear 30 and the shafts 26 and 21 -.havessecurcd thereto gears .31 and 32, respectivelr, which mesh with the gear 30.

The; shafts. 52B and 2! are disposed in spaced apart parallel relation .and it will be understood that each chuck or tool carrier may have secured thereto an internally threading tool such as. a tap. an externally threading tool such as a thread has been out. It will also be understood that. the chucks or tool carr-iers'28 and Z9-may have mountedxtherein drills, reamers or other suita'blerotary cutting tools.

' There are disposed'below the shafts 26 and ably engages.

oppositely disposed cam members 38 and 35 associated with the spindles 2B and 21, respec tively.

The cam members 38 and disposed so that the carriage pull rods 33 and 34 will be alternately moved in the direction of the headstock l2. thereon, as shown in Figure 3, a sliding or float- 39 i are ohhhsheiy" 1 Each pull rod" has mounted ing collar 40 against which a spring 4i bears and the spring 4| at its: rear end bears against a collar 42 which is secured to or fixed-on the rod 34. -A second spring 43, preferably lesser instrength than that .of' spring 4! to compensate for the resistance 'developed' at the workpiece during engagement therewith with the tap or die, is disposed'about'the rod 34 bearing, at its forward end against'the rear side of collar 42 and bearing at its-"rear end against the rear wall [4 :to'return the rod' to an outwardly extended position pushing thecarrier' 59 :to its loading position, as shown in Figure 3, on completion of the work cycle. .collar 44 is adjustably secured on the rear portion of the pull rod 34 and is adapted to limit the forward sliding movement of this rod A rear stop whereas a second or forward collar 45 is adjustably fixed on the pull rod 34 forwardly of ,the front wall l5 and is adapted to limit the rearward sliding movement of pull rod 34. .two rods 33 and 34 extend in upwardly spaced parallel relation to the top wall latter isformed after the manner of a tray ,forwardly of the-headstock l2 by means of up- The I I and the Wardly extending flanges 46 which may be formed integral with the wall H; The spring' 4! is stronger than the spring 43 so' that collar All and spring 4| act as an overload safety de- ,vice, and the members 48 and 4| cooperate with 'the spring 43 and fixed collar 42. to provide a resilient work table feed. If the spring 4i were would Further, if-the springs 4| tion of the device would be unpredictable and undependable.

A collector or sump 41 is disposed below the top wall H and the latter is formed with an 'opening 43 so that the cutting fluid discharged into the tray formed by the flanges 46 will'drain into the sump 41. The wall H has secured'to the upper side thereof a pair of lengthwise extending guides 49 which in the present instance are secured to the wall H by fastening devices 50. Each guide member 49 is formed-With'a lengthwise extending and upwardly'opening groove 5| within which an elongated key '52 slidtion of the key 52 isadapted to engage "and the gkey 52 :is clamped :in theslot or groove. 55 by "The key 52 .is adjustably se- ;cured to a carriage, generally designated'at 53. The carriage 53- includes an upright 54 which -,:is=formed with a groove 55 within which a por- "tight, the pull rod 34 will also vbe-tightly clamped to the upright 54. The upright 54 at its upper end has secured thereto a work carrier table or "plate 59 on which the work is adapted to be secured to that the work may be engaged by the tool mounted in the spindle chuck as the carriage is moved toward the chuck.

The base 15 has mounted therein a pump 60 :which may be operated by any suitable power device and the intake side of the pump BI] is connected by means of a pipe 61 to the sump or collector 41. The outlet or pressure side of the pump 60 is connected by means of a pipe 62 to a manifold 53 and the latter has extending-there:- from a pair of valved nozzles 64 which overlie the pull rods 33 and 34. The base I!) has closure plate 65 on the forward wall thereof which 'is removably secured by means of latch members 66.

In the use and operation of this device the work is secured on the work tables or carriers 59 and the desired'tool such as a die, tapydrill, reamer or the like is mounted one in each of the chucks, 28 and 29. When the motor 23 is operated drive shaft [8 will rotate thereby turning cam shaft 31 clockwise as viewed in Figure 3. Carriage pull rod 34 will initially be pulled-forwardly toward the headstock i2, cam 39 moving collar-4U rearwardly and compressing spring 4| as it-overcomes the resistance to the movementof rod 34 developed at the workpiece carried by tableh59 as it is engaged by the tap or die during the work cycle. It will of course be understood that where a tap or die is 'mounted in a spindle chuck'this tap or die will beof the bit retracting type so that when the desired length of thread has been cut the bits will be retracted and at thistime springs 4| and 43 will move pull rod 34 to the right so as to disengage the work from the tool. The use of the springs 41- and 43 will provide. a cushioning means for the feeding of the-carriage so that this carriage will not be moved-forwardly toward the headstock entirely by the threading action of the die or tapwhich is engaged with the work. By having the cam members 38 and 39 oppositely disposed one carriage will be moved forward while at the same time the other'carriage will be moved rearwardly to a work removing and loading position. In this manner the work'per- "formed by the machine will be substantially continuous as there will be one piece of Work engaged with the tool continuously. It will be understood-that there-may be two or more of these spindles or, if desired, only one spindle'may be used. With two or more spindles-the'work may be operated upon on a production basis and the character of the work performed will be accurate.

I claim:

1. A machine tool "comprising a base, ah'eadstock carried'by said base, a spindle rotatably carried by said headstock, drive meansfrota'ting said spindle, a work carriage, means "supporting said carriagefor movement 'relativ'etofisaid spindle, a pull'rodfixed to said carriage'and slidably engaging through said headstock, a collar fixed on said rod, a spring about said rod bearing at one end against said fixed" collar, a second collar slidable on said rod, and engaging against first mentioned spring to yieldably move said car riage toward said spindle and a second spring about said rod engaging between said fixed collar 7 and a fixed portion of said headstock to constantly urge said rod to an extended position so as to move said carriage away from said spindle on completion of a work cycle, the spring behind the floating collar being stronger than the spring behind the fixed collar. v

2. A machine tool comprising a base, a head stock carried by said base, a spindle rotatably carried by said head stock, a work carriage slidably carried by said base for movement toward or away from said head stock, a pull rod slidably engaging through said head stock, means adjustably securing said carriage lengthwise of said pull rod, a collar fixed on said rod within said head stock, a spring about said rod between said collar and the rear end of said head stock constantly urging said rod and carriage away from said head stock, a second collar slidable on said rod within said head stock, a second spring between said first and second collars, a cam operatively coupled with said spindle for rotation 3. A machine tool comprising a base, a headstock carried by said base having a fixed wall, a spindle rotatably carried by said headstock, drive means rotating said spindle, a work carriage, means supporting said carriage for movement relative to said spindle, a pull rod fixed to said carriage and slidably engaging through said headstock, a collar fixed on said rod at a point disposed from said fixed wall, a spring about said rod bearing at one end against said collar with the other end engaging said fixed wall and adapted to constantly urge said rod to a retracted position, a second collar slidable on said rod and disposed between said fixed collar and said carriage, a second spring about said rod engaging betweensaid first collar and said second slidable collar, means connected with said rotating means engaging said second collar for moving the latter and thereby compressing said second spring whereby to yieldably move said carriage toward said spindle, said latter named means including a rotatable cam so arranged and constructed as to compress said springs during a portion of the revolution thereof, and to release said springs during the remainder of each revolution-thereof for return of said carriage'to inoperative and loading position, said first mentioned spring being of lesser strength thanthe second mentioned spring for cooperative operation of both springs toefiect substantially equal response to movement of the cam under conditions of varying resistance developed at a workpiece carried by the carriage.

- HARVEY E. PRUITT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 402,759 Miller May 7, 1889 691,199 Stephans Jan. 14, 1902 698,828 Ferry Apr. 29, 1902 738,989 Dicke Sept. 15, 1903 1,068,126 Hamilton July 22, 1913 1,446,557 Godfriaux Feb. 27, 1923 1,460,088 Wilson June 26, 1923 1,691,825 Pruitt Nov. 13, 1928 1,847,979 Pruitt Mar. 1, 1932 2,189,152 Procunier 1, Feb. 6, 1940 

